Wavelength tunable semiconductor laser devices supply optical power and signals used in applications where precise wavelength control must be maintained, such as optical wavelength division multiplexing (WDM) communication systems and fiber optic networks. The wavelength of the output of tunable laser devices varies based on a feedback control system. This control system will utilize some form of wavelength dependent optical filters to control the wavelength of the light input to the gain medium of the laser device. Wavelength references will further stabilize the laser output of the device.
Existing tunable lasers may use a combination of independently fabricated silicon and III-V semiconductor based optical components. III-V semiconductor materials are not as effective compared to silicon materials for making low loss, compact, wavelength tunable filters, while silicon materials are not as optically efficient as III-V semiconductor materials for emitting light. Thus, in the prior art, utilizing silicon-based wavelength filters and having optically active regions with the optical efficiency of III-V semiconductor-based devices requires the combination of separately formed silicon and III-V semiconductor based optical elements. This combination of separately formed optical elements results in a larger optical devices requiring a complex manufacturing processes not on a wafer scale (e.g., hermetic packaging to couple the devices formed on different substrates, precise alignment for the elements, etc.).
Descriptions of certain details and implementations follow, including a description of the figures, which may depict some or all of the embodiments described below, as well as discussing other potential embodiments or implementations of the inventive concepts presented herein. An overview of embodiments of the invention is provided below, followed by a more detailed description with reference to the drawings.